In order to achieve a fixed-frequency and fixed-phase control system, it is described in IEEE Transactions on Communications, Vol. 37, No. 2, 1989,pages 159 to 163 to provide an additional AFC loop in addition to the narrow-band PLL loop. A quadricorrelator is suitable as a frequency error detector for the processing of digital signals.
A common frequency and phase regulation device, in which decimation occurs before the loop filter of the AFC loop and interpolation occurs afterward, is described in EP 583 643 A1. A quadricorrelator is also used therein as the frequency error detector.